Smaller fin, should make it easier to turn, assuming it is the same template just smaller then the base would be a bit narrower so I'd guess you'd lose a pinch of drive but you could probably turn it harder so it would get on a rail earlier and that is better anyway.
You'll probably lose a bit of hold, as it will be shorter in height but if your not hanging them, it won't matter.
Best way to find out is to buy one and try it.
Usual fin disclaimer, what works for me, probably won't work for you. What works in one board probably won't work in another.
funky fin 
